Rohm Plans to Commercialize Compact Fuel Cell for Smartphones

The newly-developed small fuel cell. In her left hand is a sheet formed by mixing calcium hydride and resin.

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The "cover type" (left) and "card case type" (right) of the fuel cell, which have a generation capacity of 5Wh, for smartphones. They have a rated voltage of 5.2V and a rated current of 0.5mA.

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The 200W portable power generator is used to power an LCD TV and a notebook computer. The generator has a rated output of 200W and a rated voltage of 12V or 24V.

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The 400Wh fuel cell for seismometers. It is expected to be used in remote places where no power supply is available. The weight of the cell is 3kg, which is 1/4 that of an existing lead battery.

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Rohm Co Ltd, Aquafairy Corp and Kyoto University announced Sept 18, 2012, that they have co-developed a small fuel cell as a portable power supply for smartphones, etc.

It is a polymer electrolyte fuel cell (PEFC) that generates electricity by using hydrogen generated by the reaction of a hydrogen-generating metal material and water.

In the past, Aquafairy had been developing a similar fuel cell by itself. But Aquafairy and Rohm started to exchange information after Rohm found Aquafairy's technologies at Advanced Electronics Symposium (AES) 2010, which took place at Kyoto University in the autumn of 2010, resulting in the co-development.

Aquafairy developed a small fuel cell that generates electricity by the reaction of a hydrogen-generating metal material and water in collaboration with NTT Docomo Inc and announced it in July 2006. The two companies agreed to form a business/capital alliance in September 2006 but ended up not forming a capital alliance.

The newly-developed small fuel cell is more advanced than the one announced in 2006 for two reasons. First, as a hydrogen-generating metal material, calcium hydride is used in place of magnesium hydride.

The reactivity of magnesium hydride is low at low temperatures and high at high temperatures, making it difficult to ensure stable reactions. On the other hand, calcium hydride has a very high reactivity with water at a wide range of temperatures. Therefore, stable reactions can be realized just by taking measures to suppress reactions. Specifically, a resin is added to calcium hydride.

Second, it became possible to make a cell by insert molding with a resin. In the past, a cell was formed by swaging a metal. With those technologies, about 4.5L of hydrogen can be generated by forming a sheet of calcium hydride, which measures 38 x 38 x 2mm and has a volume slightly less than 3mL, and inducing a reaction between the sheet and water.

With the hydrogen, the small fuel cell can supply an electricity of 5Wh, which can be used for fully charging a smartphone.

This time, Rohm, Aquafairy and Kyoto University announced (1) the "cover type" and "card case type" of the fuel cell, which have a generation capacity of 5Wh for smartphones, (2) a portable power generator with an output power of 200Wh and (3) a 400Wh fuel cell for seismometers, which was developed in collaboration with Kinkei System Corp, at a press conference.

They plan to evaluate the reliability of the fuel cell, make further improvements to it and commercialize it in 2013. Also, the fuel cell for seismometers is scheduled to be released in April 2013.

The newly-developed small fuel cell will be exhibited in Rohm's booths at CEATEC Japan 2012, which will take place from Oct 2 to 6, 2012, in Chiba Prefecture, Japan, and at Electronica 2012, which will run from Nov 13 to 16, 2012, in Munich, Germany.